A number of cover assemblies have been previously developed to cover all or portions of the bed of full size, mid-size and light pick-up trucks. Examples of such previously developed cover assemblies are disclosed in U.S. Pat. Nos. 3,649,073; 5,002,329; 5,102,185; and 5,366,266. The cover assembly illustrated in U.S. Pat. No. 5,102,185 is of the hatch back type in that the cover pivots about a point adjacent the cab of the vehicle. This type of cover has the inherent disadvantage of not being able to transport objects having heights greater than the height of the cab of the vehicle without first removing the cover assembly completely. In addition, this type of cover is always readily visible detracting from the overall aesthetic appearance of the pick-up truck or other vehicle. One variation of the type of cover assembly disclosed in U.S. Pat. No. 5,102,185 is a hatch back type cover with a lower profile, i.e. a cover assembly whose height is substantially less than the height of the cab of the vehicle. This type of cover assembly limits even further the type of objects which can be transported without removing the cover. In addition, the low profile of this type of cover assembly makes it difficult to remove the objects stored directly adjacent the cab of the vehicle.
The cover assemblies illustrated in U.S. Pat. Nos. 5,002,329; 5,102,185; and 5,366,266 are similar in that the covers are mounted to complex support frames which are manually raised and lowered to gain access to the bed of the pick-up truck. These cover assemblies suffer from a number of inherent disadvantages. Specifically, the covers must be manually raised via a complex support structure. In addition, these cover assemblies only move in one direction thereby limiting the manner in which access can be gained to the bed of a pick-up truck. Further, the supporting structure is such that the bed of the pick-up truck cannot be effectively and inexpensively sealed. Finally, the support structure of these cover assemblies leads to an unsightly profile for the cover assembly.